The U.S. Environmental Protection Agency today announced significant progress in the cleanup of the office of Senate Majority Leader Thomas Daschle (D-S.D.) in the Hart Senate Office Building in northeast Washington, D.C. The critical phase of the project using chlorine dioxide gas ended yesterday. Chlorine dioxide gas is regularly used to decontaminate drinking water systems, fruits and vegetables; EPA used it for the first time to fumigate office space and kill anthrax spores. EPA Administrator Christie Whitman said, “I am very proud that several weeks of planning have so successfully paid off. EPA has worked hard to ensure the public safety of neighboring residents and workers during the historical cleanup of the Hart Building. The immediate good news is that extensive and thorough air monitoring outside the building confirmed there was no threat to public health from the fumigation action. I have all the confidence in our EPA team.”

EPA On Scene Coordinator Rich Rupert said: “EPA routinely works in high-threat situations which is why a great deal of preparation goes into developing well thought out health, safety and work plans, often with the help of the U.S. Coast Guard. These plans are rigorously followed with strict protocols. In addition, there is always an equal number of workers plus one who are on hand to rescue workers who are in the hot zone.”

The first step in the cleanup included constructing isolation barriers in the office suite. After raising humidity levels in the 3,000 sq. foot office, fumigation began about 3:15 a.m. and ended at 11:30 p.m on Dec. 1. The office remained isolated while a machine emitted the gas and today also removed the chlorine dioxide gas out of the air, using a different chemical, sodium bisulfite. EPA is also cleaning eleven other offices and areas in the Hart building using different technological methodologies such as chlorine dioxide liquid, foams and HEPA vacuum.

To test the scientific effectiveness of the chlorine dioxide gas, three thousand test strips of benign surrogate spores believed to be more hearty than Bacillus anthracis were placed in Daschle’s suite. These test strips will be analyzed to help assess the effectiveness of the fumigation process. Other environmental sampling will be done in the suite to assess the effectiveness of the fumigation process. Preliminary confirmation results on both types of samples are expected within five to seven days once test samples have been collected.